active devices are the devices in which we can control
current or flow of electron electrically i.e. by use of
current or voltage.
e.g. transistors,triacs etc
in passive devices we cant control it
An active device is any type of circuit component with the ability to electrically control electron flow (electricity controlling electricity). In order for a circuit to be properly called electronic, it must contain at least one active device. Active devices include, but are not limited to, vacuum tubes, transistors, silicon-controlled rectifiers (SCRs), and TRIACs.
Components incapable of controlling current by means of another electrical signal are called passive devices. Resistors, capacitors, inductors, transformers, and even diodes are all considered passive devices.
active divices- require some extrenal energy to be ready
for an operation. these are the devices which increases the
passive devices- this devices does not require a source of
energy for operation. it only changes the phase and
decrease the amplitude of a sine wave.